1. Field of the Invention
The present invention relates to a bearing structure and a turbocharger each including a bearing which is attached to a housing of a turbocharger while penetrating the housing.
2. Background of the Related Art
Variable geometry system turbines have been used for turbochargers and the like. As disclosed in Japanese Patent Application Laid-Open Publication No. 2013-163972, in a variable geometry system turbine, multiple nozzle vanes are disposed annularly in alignment with each other in a passage through which to guide an exhaust gas to a turbine wheel from a scroll passage on the turbine side, and are fixed to their respective vane shafts. The vane shafts are rotatably supported by their respective shaft holes formed in the wall surface of the passage. Depending on how much the nozzle vanes change their angles inside the passage in response to the rotations of the corresponding vane shafts, the area of the passage changes, and the flow rate of the fluid flowing through the passage is accordingly controlled.
The vane shafts are rotated by power from an actuator. A power transmission mechanism is arranged between the actuator and the vane shafts. The power from the actuator is converted by the power transmission mechanism into power which works in either direction in which to rotate the vane shafts. The actuator is provided outside the housing of the turbocharger. In order to transmit the power to the vane shafts situated inside the housing, the power transmission mechanism includes: a bearing which is press-fitted in a through-hole penetrating the housing; and a drive shaft supported by the bearing.